Project Summary
Anatomical atlases are spatial reference maps of cells in tissues/organs/brains and provide structure
information for a wide range of biological analyses. The anatomical atlas of C. elegans nervous system is the
only atlas for the entire nervous system of an animal with a resolution of all neuronal classes. However, built on
a limited dataset and manual annotations, the standard atlas is insufficient in capturing biological variabilities,
inaccurate and difficult to use for cell identification routinely, and only applicable for wildtype adult. While several
heroic efforts of generating and imaging marker strains to build atlases have much improved the atlases, there
is still a need for a pipeline to build accurate genetic-background-specific (or experimental-condition-specific)
atlases easily and cheaply; further, there is a need to build such atlases that can be used without specialized
equipment and with as few genetic perturbations as possible. Recent development of machine learning
techniques and molecular transgenic approaches enabling the systematic production of in vivo reporters and
imaging methods capable of collecting and processing high-resolution datasets at a large scale. The goal of this
application is to address the current bottleneck by establishing a combined experimental and computational
pipeline for modularly built, complete, coordinate- and template-free brain atlases for democratized and
flexible uses. By imaging in vivo markers in a large number of live animals, the project will generate complete
anatomical atlases for the C. elegans nervous system that capture variability in the population, which will greatly
enhance the accuracy of identity predictions when used on each animal. The project will generate a collection of
transgenic animals expressing partly overlapping in vivo markers that cover all neurons and build a
computational pipeline to assemble the atlases. Further, a few widely applicable developmental atlases as a
direct output of the project will showcase the pipeline and the approach. Importantly, the atlases do not seek to
provide a set of rigid coordinates for each neuron class, but instead, a set of constraints that can be used to
provide best estimates of neuron identities for each new sample. This ensures accuracy and applicability
of the atlases to specific use case. The building of whole-brain atlases is piece-wise from easily-obtained partial
atlases, and can be crowd-sourced if desired. The use will be streamlined with image input and neuron-identity
prediction output. The proposed project is innovative, because it will build the first complete anatomical atlases
of a nervous system using large datasets collected from in vivo markers of many live animals; it uses relational
information uniquely suited to provide more accurate assignments; it will capture variabilities among individual
animals. The proposed the work is significant, because it will address the urgent and unmet need for accurate,
easy-to-use and easily updatable atlases to curate the brain; further, it will develop and establish conceptual
framework and techniques for similar efforts in more complex anatomical systems.